BECHER, bĕk'ẽr, Johann Joachim (1635-82). A German chemist, born at Speyer. He acquired an extensive knowledge of medicine, physics, chemistry, and economics; then taught and practiced medicine at Mainz. Later he founded a chemical laboratory at Munich, and in 1660 he was called to Vienna to inaugurate extensive commercial and industrial establishments. Becher had many enemies, and was accused — not altogether unjustly — of charlatanry. In his Physica Subterranea (1669), we find the first clear mention of the imaginary fiery principle (‘terra pinguis’). which afterwards, under the name of phlogiston, played so important a role in chemical theory. Consult Erdberg-Krezenciewski, Johann Joachim Becker (Jena, 1896).